Compilare: user.cpp: In function ‘int main()’: user.cpp:28:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (K >= (1ULL << (N-2))) { ^ user.cpp:9:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FILEIN, "r", stdin); ^ user.cpp:10:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FILEOUT, "w", stdout); ^